Experimental Identification of Mechanical System with Character Matrices. Study of the Physical Meaning of the Obtained Matrices and Proposal of an Improved Method.

Abstract

Experimental identification of a mechanical system with character matrices is practically convenient as it is possible to express a complicated system with a few degrees of freedom. However, the result is often affected by the measurement noise, and the elements of the obtained matrices sometimes do not directly correspond to the physical system. The former has lately been discussed and improved, but the latter remains a problem. In this paper we first discuss the physical meaning of the obtained matrices, whatever the identification method may be. Next, we propose an improved method based on an assumption that the system includes only proportional damping. The method was examined both numerically and experimentally, and proved to be practical.